Heat related mortality in warm and cold regions of Europe: observational study
Saving lives in extreme weather in summer
Heat related deaths start at higher temperatures in hot regions of Europe compared to cold regions, suggesting that people have adjusted successfully to differences in summer temperatures across Europe, and can be expected to adjust to the global warming predicted in the next 50 years, according to a study in this week's BMJ.
A team of European researchers calculated the average number of deaths among men and women aged 65-74 years at successive 3C temperature bands across seven European regions - north and south Finland, south west Germany, Netherlands, London, north Italy and Athens. The authors found for each region the 3C temperature band in which there was least mortality, and found that this band was significantly higher in hotter regions (14-17C in north Finland and 23-26C in Athens). As a result, when temperatures rose above these bands, regions with hot summers did not have significantly more heat related deaths than cold regions.
The team also found that cold related deaths were much more numerous than heat related deaths, across all regions. They were 78 times more numerous than heat related deaths in London, which had the highest rate of cold related deaths of any region.
These findings suggest that populations in Europe have adjusted to differences in average summer temperatures ranging from 13.5C to 24C. This gives grounds for confidence that they would also adjust - with little increase in heat related deaths - to the global warming of around 2C predicted to occur in the next 50 years, say the authors. However, the authors suggest that pre-emptive measures against heat stress, such as improving ventilation in the homes of vulnerable people, in advance of global warming should be considered.
Their most important conclusion is that cold will continue to cause massive mortality every winter, particularly in Britain, unless effective steps are taken to improve protection against cold stress.
W R Keatinge, Professor of Physiology, Queen Mary and Westfield College, London, UK